A beverage bottle that opens manually with relative ease, without the use of a bottle opener, has been a long-felt need for beverage providers. Bottle caps must be tightly secured to the bottle opening to prevent spillage of the contents, loss of pressure (in the case of pressurized or carbonated beverages) and to maintain the hygienic conditions of the contents. The tight seal makes it difficult to open a bottle by hand.
Caps, also referred to interchangeably as crowns, are secured to the bottle opening by crimping the crown down over the open of the container in a series of concave arcs around the circumference of the opening. The arcs create sharp convex points between each concave arc. The arcs and points are often referred to by those skilled in art as “angles” or “flutes.”
The advent of the familiar twist-off bottle cap was a significant advance for manual bottle opening, but all too frequently one has to grip the cap so hard to twist the cap free that the points of the cap angles inflict pain on the hands or fingers. To protect the hands from injury, it is a common practice to wrap the bottle cap in the tail of a shirt or in a cloth before twisting the cap.
Bottle caps adapted with pull tabs, similar to those used for beverage cans, have been known in China and other territories of Asia. See, for example, International Patent Application PCT/CN00/00040 by Liu, priority date Mar. 4, 1999, International Publication No. WO00/51906. Such pull tab bottle caps, however, are notoriously difficult to open because they require the exertion of an uncomfortable amount of force to break the seal and then pull the tab back (tearing the metal) to remove the cap.
Another pull-tab solution for bottle caps is known as the MaxiCrown® such as is described U.S. Pat. No. 4,768,667, issued Sep. 6, 1988, to Magnusson. The MaxiCrown® provides a pull ring disposed along the side of the neck of the bottle as an extension of the crown and thus is problematic for use with standard angle-crimping bottle capping machines. Indeed, a special capping machine is recommended to cap bottles with the MaxiCrown®.
There is a need, therefore, for a bottle crown that is easy to open manually yet which may be tightly sealed around the bottle opening using standard bottle capping machines common in the art.